1. Field of the Invention:
The present invention relates to a photographic camera provided with a mechanism for recording data, such as exposure data, and more particularly to an improvement of a photographic film transporting system.
2. Description of the Related Art:
In a conventional photographic camera, an auto-loading mechanism is incorporated, for facilitating photographic film-loading, wherein the leading end of a photographic film leader is automatically captured on a take-up reel in a photographic film take-up chamber. Before loading, the photographic film leader of the conventional photographic film cassette is maintained in a state in which it protrudes from a photographic film passage mouth of the cassette shell. The protruded photographic film leader is inserted together with the cassette shell in the camera, fed to the photographic film take-up chamber by the auto-loading mechanism, and captured on the take-up reel.
A camera, in which photographic film provided with a magnetic recording area is utilized and which reads/writes data thereon, is known and is disclosed in International Publications WO 90/04201 and 90/04202. This camera incorporates a magnetic head, which reads/writes data on the magnetic recording area while the photographic film is transported between the photographic film take-up reel and the photographic film cassette. Such data includes photographic film data, e.g., type of photographic film, photographic sensitivity, numbers of frames and the like, as stored during a manufacturing process, for use in taking photographs, and photo-taking data as written during photo-taking for use in making prints.
Also, a photographic film cassette is known in which a photographic film leader does not originally protrude from the cassette shell, and which is thus more easily loaded in a camera. Such a film cassette is disclosed in U.S. Pat. Nos. 4,832,275, 4,834,306, and 4,846,418. Rotation of a spool core by means of the fork of the camera in the direction of unwinding the photographic film causes the photographic film leader to advance to the outside of the cassette shell through the photographic film passage mouth. The cassette shell is provided with a device, e.g., annular ridges, for preventing the roll of photographic film from loosening when the spool core is rotated. Such a cassette transmits the rotary force of the spool core to the photographic film leader.
Because the photographic film is kept wound in the roll in the conventional photographic film cassette, a strong tendency to curl remains in the photographic film even when unwound. The photographic film of the above-described type of photographic film cassette has an additional curling tendency in the photographic film leader. Curl in photographic film causes problems in the camera when the photographic film is advanced and transported. When the take-up reel is rotated to transport the photographic film, the fork is left free, whereas the former is left free when the latter is rotated to transport the photographic film. In cameras with the above-described photographic film transporting system, the photographic film is flexed on lateral sides of the magnetic head due to the intermittent photographic film feeding. Accordingly, difficulties may arise in reading/writing data adequately due to poor contact between the film and a magnetic head.
As illustrated in FIG. 8, during advancement of the photographic film leader of photographic film 3 toward a take-up reel 30 in the initial stage of photographic film transportation, the photographic film leader has a strong tendency to curl downward in FIG. 8 and thus moves in a photographic film take-up chamber 73 along its inner wall upstream from the take-up reel 30. Accordingly, the leading end of the photographic film leader may fail to be captured on the take-up reel 30, making it impossible to load the camera with the photographic film contained in the leader-propelling photographic film cassette.